Junk button moves, but can also forward message

there are two magic LDAP config attributes zimbraSpamIsSpamAccount and zimbraSpamIsNotSpamAccount - if set then then these addresses are emailed a copy of the message. Soon (not in the release that's coming up, but hopefully in the one after that), we will have that wired up to feed SA's bayes, and empty the accounts etc.

Any of you non-Zimbra (yet) folks using SA and have Bayes turned on in a multi-mailbox setup?

Just gave Zimbra a first look on an virtual FC 4 in VMWARE ESX and it works great.
I am currently running an Squirrelmail Setup for 150 Users ( http://koelnerabend.de ) and I allow user based training of the bayes filter. Due to a lot of stupid users, I had to switch from overall training to a user based setup. With a good training, the user will get up to 97% accuracy.
I seriously consider to change to Zimbra, but I will do some load tests first.